The proposed project will investigate the molecular mechanism of the stable cholinergic-muscarinic inhibition of adenylate cyclase in rat parotid membranes. Binding of Beta-adrenergic agonists and antagonists will be investigated. Solubilization and reconstitution experiments will be performed to identify the site of inhibition. In addition to that, preliminary work will be done to identify the site of the cholinergic modulation of the metabolism of phosphatidylinositol and the identification of the biochemical reactions involved.